Protected components in electrochemical devices

ABSTRACT

A component of an electrochemical device includes a substrate made of stainless steel, where the substrate is further characterized by a microstructure containing an intermetallic compound. A component of an electrochemical device includes a substrate having at least one surface, where the substrate is made of stainless steel. The component further includes at least one surface coating layer on each of the at least one surface. Each of the at least one surface coating layer includes a carbide material or a MAX phase material.

TECHNICAL FIELD

The present disclosure relates to protected components in electrochemical devices, for example, metal components in a fuel cell or electrolyzer system, such as bipolar plates, fuel storage tanks, connecting pipes, or safety valves, protected with anti-corrosion materials against hydrogen-related degradations (e.g. hydrogen embrittlement).

BACKGROUND

Metals have been a widely used material for thousands of years. Various methods have been developed to preserve metals and prevent their corrosion or disintegration into oxides, hydroxides, sulfates, and other salts. Metals in some industrial applications are especially susceptible to corrosion due to aggressive operating environments. A non-limiting example may be metal components of a fuel cell (e.g. bipolar plates). For instance, bipolar plates are required to be not only sufficiency chemically inert to resist degradation in a highly corrosive environment of the fuel cell, but also electrically conducting to facilitate electron transfer for the oxygen reduction reaction of the fuel cell. Finding a material that meets both the requirements of anti-corrosion and electric conduction has been a challenge.

SUMMARY

According to one embodiment, a component of an electrochemical device is disclosed. The component may include a substrate made of stainless steel characterized by a microstructure containing an intermetallic compound.

According to another embodiment, a component of an electrochemical device is disclosed. The component may include a substrate having at least one surface. The substrate may be made of stainless steel. The component may further include at least one surface coating layer on each of the at least one surface. Each of the at least one surface coating layer may include a carbide material. The carbide material is a carbide compound. The carbide compound may be Ni₆Mo₆C, Cr₂₁Mo₂C₆, Fe₂₃C₆, Ni₂Mo₄C, Mn₃Mo₃C, Si₃Mo₅C, Mn₇C₃, Mn₅SiC, or a combination thereof.

According to yet another embodiment, a component of an electrochemical device is disclosed. The component may include a substrate having at least one surface. The substrate may be made of stainless steel. The component may further include at least one surface coating layer on each of the at least one surface. Each of the at least one surface coating layer may include a MAX phase material. The MAX phase material is a MAX phase compound with a general formula of M_(n+1)AX_(n), where n=1 to 4, M is an early transition metal, A is an A-group element (e.g. IIIA, IVA, group 13, or group 14 element), and X is either C or N. The MAX phase compound may be Nb₄AlC₃, Ti₄AlN₃, Nb₂SnC, Ti₃SnC₂, Zr₂SC, Ti₂SnC, Zr₂SnC, Nb₂PC, Nb₂AlC, Ti₃SiC₂, Ti₃AlC₂, Ti₂SC, V₂PC, or a combination thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a chemical space of Fe—Cr—Ni—Mn—Mo—Si—O.

FIG. 2 depicts a schematic diagram of a computing platform that may be utilized to implement a data-driven materials screening method.

FIG. 3 depicts a schematic phase diagram showing a reaction enthalpy (eV/atom) of a reaction between Fe and H₂ as a function of a molar fraction of H₂ in a reaction environment.

FIG. 4 depicts a schematic phase diagram showing a reaction enthalpy (eV/atom) of a reaction between Si and H₂ as a function of a molar fraction of H₂ in a reaction environment.

FIG. 5A is a schematic cross-sectional view of a fuel cell.

FIG. 5B is a schematic perspective view of components of the fuel cell shown in FIG. 5A.

DETAILED DESCRIPTION

Embodiments of the present disclosure are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments can take various and alternative forms. The figures are not necessarily to scale; some features could be exaggerated or minimized to show details of components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the embodiments. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures can be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for applications or implementations.

This present disclosure is not limited to the specific embodiments and methods described below, as specific components and/or conditions may, of course, vary. Furthermore, the terminology used herein is used only for the purpose of describing embodiments of the present disclosure and is not intended to be limiting in any way.

As used in the specification and the appended claims, the singular form “a,” “an,” and “the” comprise plural referents unless the context clearly indicates otherwise. For example, reference to a component in the singular is intended to comprise a plurality of components.

The description of a group or class of materials as suitable for a given purpose in connection with one or more embodiments implies that mixtures of any two or more of the members of the group or class are suitable. Description of constituents in chemical terms refers to the constituents at the time of addition to any combination specified in the description and does not necessarily preclude chemical interactions among constituents of the mixture once mixed.

Except where expressly indicated, all numerical quantities in this description indicating dimensions or material properties are to be understood as modified by the word “about” in describing the broadest scope of the present disclosure.

The first definition of an acronym or other abbreviation applies to all subsequent uses herein of the same abbreviation and applies mutatis mutandis to normal grammatical variations of the initially defined abbreviation. Unless expressly stated to the contrary, measurement of a property is determined by the same technique as previously or later referenced for the same property.

The term “substantially” may be used herein to describe disclosed or claimed embodiments. The term “substantially” may modify any value or relative characteristic disclosed or claimed in the present disclosure. “Substantially” may signify that the value or relative characteristic it modifies is within +0%, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5% or 10% of the value or relative characteristic.

Reference is being made in detail to compositions, embodiments, and methods of embodiments known to the inventors. However, disclosed embodiments are merely exemplary of the present disclosure which may be embodied in various and alternative forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, rather merely as representative bases for teaching one skilled in the art to variously employ the present disclosure.

Ferrous materials, such as steel, are commonly used to fabricate components in an electrochemical device, such as in a fuel cell or electrolyzer system. Non-limiting examples of these components are bipolar plates, fuel storage tanks, connecting pipes, safety valves, or heat exchangers. Although ferrous materials provide an economical and viable solution to manufacture these components, the materials are susceptible to hydrogen-related degradations, such as hydrogen embrittlement, when they are exposed to hydrogen (H₂). Hydrogen embrittlement may make the materials brittle, leading to a significant loss of ductility of the materials.

H₂ gas is one of the reactants used in a fuel cell system, making metal components in the fuel cell system susceptible to hydrogen-related degradations. Similarly, because H₂ gas can be produced via an electrolysis process conducted by an electrolyzer system, metal components in the electrolyzer system may be exposed to the produced H₂ gas and subject to hydrogen-related degradations. Therefore, in order to maintain a healthy environment in the fuel cell or electrolyzer systems as well as other electrochemical devices, there is a need to protect the metal components in these electrochemical devices from hydrogen-related degradations.

Aspects of the present disclosure relate to a material which may be applied to or formed within a metal component in an electrochemical device, such as in a fuel cell or electrolyzer system, to protect the metal component from hydrogen-related degradations (e.g. hydrogen embrittlement). The metal component may be bipolar plates, fuel storage tanks, connecting pipes, safety valves, or heat exchangers. The metal component may be made of stainless steel. The metal component may also be made of Ti-based or Al-based alloys. In one embodiment, aspects of the present disclosure relate to a metal component of an electrochemical device made of stainless steel, where the stainless steel is characterized by a microstructure containing an intermetallic compound. The intermetallic compound may be Cr₃Si, Mn₃Si, SiMo₃, SiNi₂, Mn₆Si₇Ni₁₆, MnSiNi, Si₁₂Ni₃₁, Fe₃Si, Si₃Mo₅, Mn₂FeSi, FeSi, Mn₂CrSi, MnSi, MnFe₂Si, Si₂Mo, Fe₁₁Si₅, Fe₂Si, MnNi₃, Mn₂SiMo, Fe₅Si₃, Mn₄Si₇, Ni₃Mo, FeNi₃, CrSi₂, FeSi₂, Fe₂Mo, SiNi, MnCrFeSi, Fe₇Mo₆, Ni₄Mo, FeNi, FeSiMo, Si₂Ni, CrNi₃, SiNi₃, or a combination thereof. In another embodiment, aspects of the present disclosure relate to a metal component of an electrochemical device made of stainless steel, where the metal component includes at least one surface. At least one surface coating layer of a protective coating material is applied to the at least one surface. The protective coating material may be a carbide material, including Ni₆Mo₆C, Cr₂₁Mo₂C₆, Mn₂₃C₆, Cr₂₃C₆, Fe₂₃C₆, Ni₂Mo₄C, Mn₃Mo₃C, Si₃Mo₅C, Fe₃Mo₃C, Cr₇C₃, Mn₇C₃, Mn₅SiC, Mn₅C₂, Mo₂C, Mn₃C, Cr₃C₂, Cr₃C, or a combination thereof. The protective coating material may also be a MAX phase compound material, including Nb₄AlC₃, Ti₄AlN₃, Nb₂SnC, Ti₃SnC₂, Zr₂SC, Ti₂SnC, Zr₂SnC, Nb₂PC, Nb₂AlC, Ti₃SiC₂, Ti₃AlC₂, Ti₂SC, V₂PC, or a combination thereof.

Stainless steel (SS) is a generic name for different steel compositions. Typically, nearly all stainless steels contain at least 10% chromium (Cr). Cr can form a stable chrome-oxide surface layer on the SS to prevent degradation of the SS. Two most popular SS compositions are SS304 and SS316, where SS304 contains 18-20 weight percent (wt %) Cr and 8-10.5 wt % nickel (Ni), and SS316 contains 16-18 wt % Cr, 10-14 wt % Ni, and 2-3 wt % molybdenum (Mo). In addition to Cr, Ni, and Mo, SS may also include elements such as carbon (C, around 0.08 wt %), manganese (Mg, around 1 to 2 wt %), silicon (Si, around 0.5 to 2 wt %), nitrogen (N, around 0.01 to 0.1 wt %), copper (Cu, around 0.5 to 2 wt %), cobalt (Co, around less than 0.5 wt %) and the balance iron (Fe). The SS composition may vary depending on an application of the SS such that the SS can provide a sustainable mechanical stability, corrosion resistance, and magnetic property.

SS316L is one of the variants of SS316. The difference between SS316L and SS316 is that SS316L has a much lower carbon content than SS316, making SS316L suitable for welding. Particularly, SS316L includes 0.03 wt % C, 16-18 wt % Cr, 10-14 wt % Ni, 2 wt % Mn, 0.75 wt % Si, 0.01 wt % N, 0.045 wt % P, 0.03 wt % S, 2-3 wt % Mo, and the balance Fe. Converting wt % into mol % gives a chemical formula of SS316L as Fe_(65.2)Cr_(18.1)Ni_(11.3)Mn₂Mo_(1.5)Si_(1.5)C_(0.1)P_(0.1)S_(0.1). According to this chemical formula, SS316L has a small amount of C, P, or S.

FIG. 1 depicts a chemical space of Fe—Cr—Ni—Mn—Mo—Si—O, a 7-dimensional phase diagram generated on the Open Quantum Materials Database (oqmd.org). The oqmd.org is a database of density functional theory (DFT) calculated thermodynamic and structural properties of 637,644 materials. The chemical space of Fe—Cr—Ni—Mn—Mo—Si—O is relevant to the composition of SS316L. As shown in FIG. 1 , there are 64 stable compounds in four categories: binary oxides, ternary oxides (or higher), binary intermetallics, or ternary intermetallics (or higher). Each line corresponds to a two-phase equilibrium. These compounds are predicted to be stable at a temperature of 0 K (−273.15° C.) and above.

Table 1 lists the compounds defined by the chemical space of Fe—Cr—Ni—Mn—Mo—Si—O described in FIG. 1 . Additionally, Table 1 provides some other compounds which may be stable at temperatures between around room temperature and up to around 130° C. and which may be stable at temperatures between around 130° C. and up to around 250° C. Table 1 categorizes these compounds based on their types (e.g. oxides or intermetallics) and stabilities of the compounds. For example, binary intermetallics that are stable at a temperature of around 0 K include Cr₃Si, CrNi₃, CrSi₂, Fe₂Mo, Fe₃Si, FeNi, FeNi₃, FeSi, FeSi₂, Mn₃Si, Mn₄Si₇, MnNi₃, MnSi, Ni₃Mo, Ni₄Mo, Si₁₂Ni₃₁, Si₂Mo, Si₂Ni, Si₃Mo₅, SiMo₃, SiNi, SiNi₂, and SiNi₃. Binary intermetallics that are stable at temperatures between around 1 K and up to around 130° C. include Fe₇Mo₆, Fe₂Si, Mn₃Ni, Si₂Ni₃, MnFe₃, Fe₁₁Si₅, MnFe, Mn₃Fe, and Fe₅Si₃. Further, binary intermetallics that are stable at temperatures between around 130° C. and up to around 250° C. include MnCr₃ and MnNi.

TABLE 1 Compounds defined by the chemical space of Fe—Cr—Ni—Mn—Mo—Si—O described in FIG. 1. Stable when Category temperature is Compounds Binary At 0 K Cr₂O₃, CrO₂, Fe₂O₃, Fe₃O₄, FeO, Mn₂O₃, Mn₃O₄, MnO, oxides MnO₂, MoO₂, MoO₃, NiO, NiO₂, SiO₂ Between 1 K and 130° C. Mn₅O₈ Between 130° C. and 250° C. Mo₂O₃ Ternary At 0 K Cr₂SiO₄, CrNiO₄, Fe₂Mo₃O₈, Fe₂NiO₄, Fe₂SiO₄, FeMoO₄, oxides Mn₂Mo₃O₈, Mn₂SiO₄, Mn₇SiO₁₂, MnCr₂O₄, MnFeSiO₄, (or higher) MnMoO₄, MnNi₆O₈, MnNiO₃, MnSiNiO₄, NiMoO₄, SiNi₂O₄ Between 1 K and 130° C. MnSiO₃, FeSiO₃, Cr₂NiO₄, FeNiO₂, FeNi₂O₄, Fe₃Si₂O₈, Cr₂FeO₄ Between 130° C. and 250° C. MnFe₂O₄, Fe₅Si₃O₁₂, CrNi₂O₄ Binary At 0 K Cr₃Si, CrNi₃, CrSi₂, Fe₂Mo, Fe₃Si, FeNi, FeNi₃, FeSi, FeSi₂, intermetallic Mn₃Si, Mn₄Si₇, MnNi₃, MnSi, Ni₃Mo, Ni₄Mo, Si₁₂Ni₃₁, Si₂Mo, Si₂Ni, Si₃Mo₅, SiMo₃, SiNi, SiNi₂, SiNi₃ Between 1 K and 130° C. Fe₇Mo₆, Fe₂Si, Mn₃Ni, Si₂Ni₃, MnFe₃, Fe₁₁Si₅, MnFe, Mn₃Fe, Fe₅Si₃ Between 130° C. and 250° C. MnCr₃, MnNi Ternary At 0 K Mn₂FeSi, Mn₆Si₇Ni₁₆, MnSiNi intermetallic Between 1 K and 130° C. MnFe₂Si, Mn₂CrSi, FeSiMo (or higher) Between 130° C. and 250° C. MnCrFe₂, Mn₂SiMo, MnCrFeSi

FIG. 2 depicts a schematic diagram of a computing platform that may be utilized to implement a data-driven materials screening method. The computing platform 10 may include a processor 12, a memory 14, and a non-volatile storage 16. The processor 12 may include one or more devices selected from high-performance computing (HPC) systems including high-performance cores, microprocessors, micro-controllers, digital signal processors, microcomputers, central processing units, field programmable gate arrays, programmable logic devices, state machines, logic circuits, analog circuits, digital circuits, or any other devices that manipulate signals (analog or digital) based on computer-executable instructions residing in memory. The memory 14 may include a single memory device or a number of memory devices including random access memory (RAM), volatile memory, non-volatile memory, static random-access memory (SRAM), dynamic random-access memory (DRAM), flash memory, cache memory, or any other device capable of storing information. The non-volatile storage 16 may include one or more persistent data storage devices such as a hard drive, optical drive, tape drive, non-volatile solid-state device, cloud storage or any other device capable of persistently storing information.

The processor 12 may be configured to read into memory and execute computer-executable instructions residing in a DFT software module 18 of the non-volatile storage 16 and embodying DFT slab model algorithms, calculations and/or methodologies of one or more embodiments. The DFT software module 18 may include operating systems and applications. The DFT software module 18 may be compiled or interpreted from computer programs created using a variety of programming languages and/or technologies, including, without limitation, and either alone or in combination, Java, C, C++, C#, Objective C, Fortran, Pascal, Java Script, Python, Perl, and PL/SQL.

Upon execution by the processor 12, the computer-executable instructions of the DFT software module 18 may cause the computing platform 10 to implement one or more of the DFT algorithms and/or methodologies disclosed herein. The non-volatile storage 16 may also include DFT data 20 supporting the functions, features, calculations, and processes of the one or more embodiments described herein.

The program code embodying the algorithms and/or methodologies described herein is capable of being individually or collectively distributed as a program product in a variety of different forms. The program code may be distributed using a computer readable storage medium having computer readable program instructions thereon for causing a processor to carry out aspects of one or more embodiments. The computer readable storage medium, which is inherently non-transitory, may include volatile and non-volatile, and removable and non-removable tangible media implemented in any method or technology for storage of information, such as computer-readable instructions, data structures, program modules, or other data. The computer readable storage media may further include RAM, ROM, erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other solid state memory technology, portable compact disc read-only memory (CD-ROM), or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and which can be read by a computer. Computer readable program instructions may be downloaded to a computer, another type of programmable data processing apparatus, or another device from a computer readable storage medium or to an external computer or external storage device via a network.

Computer readable program instructions stored in the computer readable medium may be used to direct a computer, other types of programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions that implement the functions, acts, and/or operations specified in the flowcharts or diagrams. In certain alternative embodiments, the functions, acts, and/or operations specified in the flowcharts and diagrams may be re-ordered, processed serially, and/or processed concurrently consistent with one or more embodiments. Moreover, any of the flowcharts and/or diagrams may include more or fewer nodes or blocks than those illustrated consistent with one or more embodiments.

Referring to FIG. 2 , the data-driven materials screening method may be utilized to screen compounds that are resistant to hydrogen-related degradations (e.g. hydrogen embrittlement) or that are suitable to be used as protective coating materials to protect metal components in electrochemical devices, such in a fuel cell or electrolyzer system, from hydrogen-related degradations. The data-driven materials screening method may evaluate compounds in terms of their reactivities against H₂, including the reactivity of a compound when there is a dilute amount of H₂ or an abundant amount of H₂ in a reaction environment.

To better understand the reactivity of each compound against H₂, the data-driven materials screening method is first used to examine the reactivity of Fe against H₂ under similar conditions. The reactivity of Fe against H₂ may then be used as a reference to identify compounds that are comparably less reactive against H₂ than Fe.

FIG. 3 depicts a schematic phase diagram showing a reaction enthalpy (eV/atom) of a reaction between Fe and H₂ as a function of a molar fraction of H₂ in a reaction environment. The molar fraction of H₂ is in a range of 0 and 1. As shown in FIG. 3 , when the molar fraction of H₂ is 0, there is no H₂ and 100% of Fe in the reaction environment. Conversely, when the molar fraction of H₂ is 1, there is no Fe and 100% H₂ in the reaction environment. As the molar fraction of H₂ increases from 0, a reaction occurs at Point A, where the molar fraction of H₂ is about 0.333 and the reaction enthalpy of the reaction is about −0.059 eV/atom. Reaction (1) is expressed below to illustrate the reaction:

0.333H₂+0.667Fe→0.667FeH  (1)

According to reaction (1), after reacting with H₂, Fe is turned into iron(I) hydride (FeH). In this scenario, reaction (1) appears to be the only reaction between Fe and H₂, and FeH does not appear to further react with H₂.

FIG. 4 depicts a schematic phase diagram showing a reaction enthalpy (eV/atom) of a reaction between Si and H₂ as a function of a molar fraction of H₂ in a reaction environment. Si is one of the elements in stainless steel. The molar fraction of H₂ is in a range of 0 and 1. As shown in FIG. 4 , when the molar fraction of H₂ is 0, there is no H₂ and 100% of Si in the reaction environment. Conversely, when the molar fraction of Si is 1, there is no Si and 100% H₂ in the reaction environment. As the molar fraction of H₂ increases from 0, a first stable decomposition reaction occurs at Point B, where the molar fraction of H₂ is about 0.667 and the reaction enthalpy of the first stable decomposition reaction is about −0.107 eV/atom. The first stable decomposition reaction occurs when there is a dilute amount H₂ in the reaction environment. Reaction (2) is expressed below to illustrate the first stable decomposition reaction:

0.667H₂+0.333Si→0.333SiH₄  (2)

According to reaction (2), after reacting with the dilute amount of H₂, Si is turned into silane (SiH₄). Continue referring to FIG. 4 , as the molar fraction of H₂ keeps increasing, the most stable decomposition reaction may occur at Point C, where the molar fraction of H₂ is about 0.800 and the reaction enthalpy of the most stable decomposition reaction is about −0.116 eV/atom. The most stable decomposition reaction occurs when there is an abundant amount of H₂ in the reaction environment. Reaction (3) is included hereby to illustrate the most stable decomposition reaction:

0.8H₂+0.2Si→0.2SiH₈  (3)

According to reaction (3), after reacting with the abundant amount of H₂, Si is turned into SiH₈. Referring to reactions (2) and (3), the reaction enthalpy and the product of the reaction between Si and H₂ may depend on the amount of H₂ available in the reaction environment.

Apart from reacting with Fe and Si, H₂ may also react with other elements in the stainless steel, including Cr, Ni, Mn, and Mo. The data-driven materials screening method may be further employed to study the reactivities of these elements against H₂ under similar conditions. In each scenario, there may be a first stable decomposition reaction between the element and H₂, which occurs when the concentration of H₂ is dilute in the reaction environment. In addition, in each scenario, there may be the most stable decomposition reaction between the element and H₂, which occurs when the concentration of H₂ is abundant in the reaction environment. It may be possible that the first stable decomposition reaction and the most stable decomposition reaction between the element and H₂ are identical, like the case for Fe. The reaction enthalpy of each reaction, if possible, may also be calculated using the data-driven materials screening method.

Table 2 depicts information of a first stable decomposition reaction between a dilute amount of H₂ and Fe, Cr, Ni, Mn, Mo, or Si, respectively. Particularly, Table 2 provides a reaction equation, if possible, of the first stable decomposition reaction and a reaction enthalpy of each reaction. To easily compare the reactivity of each element against H₂, Table 2 provides a molar fraction between H₂ and each element. Table 2 further provides a penalty point (e.g. PP1) regarding the molar fraction, where PP1 of 1.00 is assigned to the reference reaction between Fe and the dilute amount of H₂. In addition, Table 2 provides another penalty point (e.g. PP2) regarding the reaction enthalpy of each reaction, where PP2 of 1.00 is assigned to the reaction enthalpy of the reaction between Fe and the dilute amount of H₂.

TABLE 2 Information of a first stable decomposition reaction between a dilute amount of H₂ and Fe, Cr, Ni, Mn, Mo, or Si, respectively. Reaction Equation of a first stable Molar enthalpy Element decomposition reaction fraction PP1 (eV/atom) PP2 Fe 0.333 H₂ + 0.667 Fe → 0.667 FeH 0.50 1.00 −0.059 1.00 (reference) Cr 0.333 H₂ + 0.667 Cr → 0.667 CrH 0.50 1.00 −0.052 0.88 Ni 0.333 H₂ + 0.667 Ni → 0.667 NiH 0.50 1.00 −0.112 1.90 Mn 0.033 H₂ + 0.967 Mn → 0.033 Mn₂₉H₂ 0.03 14.65 −0.033 0.56 Mo No Reaction N/A 0.00 N/A 0.00 Si 0.667 H₂ + 0.333 Si → 0.333 SiH₄ 2.00 0.25 −0.107 1.81

As illustrated in Table 2, Cr and Ni, when reacting with a dilute amount of H₂, require the same amount of H₂ as Fe. Mn consumes less H₂ per mol than Fe. Mo does not appear to react with H₂ when the concentration of H₂ is dilute in the reaction environment. Further, Si consumes more H₂ per mol than Fe. On the other hand, Cr and Mn appear to be comparably less reactive with H₂ when compared to Fe, and Ni and Si appear to be comparably more reactive with H₂ when compared to Fe. In summary, when reacting with a dilute amount of H₂, Mn requires the least amount of H₂ among these elements (except Mo), and is comparably the least reactive element to react with a dilute amount of H₂.

Table 3 depicts information of the most stable decomposition reaction between an abundant amount of H₂ and Fe, Cr, Ni, Mn, Mo, or Si, respectively. Particularly, Table 3 provides a reaction equation, if possible, of the most stable decomposition reaction and a reaction enthalpy of each reaction. To easily compare the reactivity of each element against H₂, Table 3 provides a molar fraction between H₂ and each element. Table 3 further provides a penalty point (e.g. PP3) regarding the molar fraction, where PP3 of 1.00 is assigned to the reference reaction between Fe and the abundant amount of H₂. In addition, Table 3 provides another penalty point (e.g. PP4) regarding the reaction enthalpy of each reaction, where PP4 of 1.00 is assigned to the reaction enthalpy of the reaction between Fe and the abundant amount of H₂.

TABLE 3 Information of the most stable decomposition reaction between an abundant amount of H₂ and Fe, Cr, Ni, Mn, Mo, or Si, respectively. Reaction Equation of the most stable Molar enthalpy Element decomposition reaction fraction PP3 (eV/atom) PP4 Fe 0.333 H₂ + 0.667 Fe → 0.667 FeH 0.50 1.00 −0.059 1.00 (reference) Cr 0.333 H₂ + 0.667 Cr → 0.667 CrH 0.50 1.00 −0.052 0.88 Ni 0.333 H₂ + 0.667 Ni → 0.667 NiH 0.50 1.00 −0.112 1.90 Mn 0.033 H₂ + 0.967 Mn → 0.033 Mn₂₉H₂ 0.03 14.65 −0.033 0.56 Mo No Reaction N/A 0.00 N/A 0.00 Si 0.8 H₂ + 0.2 Si → 0.2 SiH₈ 4.00 0.13 −0.116 1.97

As illustrated in Table 3, Cr and Ni, when reacting with an abundant amount of H₂, require the same amount of H₂ as Fe. Mn consumes less H₂ per mol than Fe. Mo does not appear to react with H₂ when the concentration of H₂ is abundant in the reaction environment. Further, Si consumes more H₂ per mol than Fe. On the other hand, Cr and Mn appear to be comparably less reactive with H₂ when compared to Fe, and Ni and Si appear to be comparably more reactive with H₂ when compared to Fe. In summary, when reacting with an abundant amount of H₂, Mn requires the comparably least amount of H₂ among these elements (except Mo), and is comparably the least reactive element to react with an abundant amount of H₂.

In view of Tables 2 and 3, the first stable decomposition reaction and the most stable decomposition reaction between H₂ and Fe, Cr, Ni, or Mn, respectively, are identical. Mo does not react with H₂. In both scenarios, Si appears to consume the most H₂, and the reaction between Si and H₂ appears to be more favorable than that of Fe.

Now, a process for screening the compounds in Table 1 is described. Specifically, the present disclosure describes the process for screening the intermetallic compounds in Table 1. Other compounds in Table 1 may be evaluated using the same or substantially the same screening process. Using the data-driven materials screening method, each intermetallic compound in Table 1 is evaluated in terms of its reactivity against H₂. Afterwards, the reactivity of each intermetallic compound against H₂ is compared with that of Fe to identify intermetallic compounds that are comparably resistant to hydrogen-related degradations (e.g. hydrogen embrittlement).

Table 4 depicts information of a first stable decomposition reaction between each intermetallic compound in Table 1 and a dilute amount of H₂. Table 4 provides a reaction equation, if possible, of the first stable decomposition reaction and a reaction enthalpy of each reaction. To take the stability of each intermetallic compound into consideration, a penalty point (e.g. PP5) is assigned to each intermetallic compound. Particularly, the intermetallic compounds which are stable at a temperature of around 0 K are assigned a PP5 of 0. Further, the intermetallic compounds which are stable at temperatures between around 1 K and up to around 130° C. are assigned a PP5 of 1. In addition, the intermetallic compounds which are stable at temperatures between around 130° C. and up to around 250° C. are assigned a PP5 of 2.

Table 4 also provides a molar fraction between the dilute amount of H₂ and each intermetallic compound. Further, Table 4 provides another penalty point (e.g. PP6) regarding the molar fraction, where PP6 of 1.00 is assigned to the reference reaction between Fe and the dilute amount of H₂ (i.e. the molar fraction is 0.50, as listed in Table 2). PP6 is calculated by dividing the molar fraction between the dilute amount of H₂ and Fe by the molar fraction between the dilute amount of H₂ and each intermetallic compound. For example, since the molar fraction between the dilute amount of H₂ and CrNi₃ is 0.50, PP6 thus equals 0.50/0.50, which is around 1.00.

Table 4 further provides a reaction enthalpy (eV/atom) of the reaction between the dilute amount of H₂ and each intermetallic compound. Table 4 also provides another penalty point (e.g. PP7) regarding the reaction enthalpy, where PP7 of 1.00 is assigned to the reference reaction between Fe and the dilute amount of H₂ (i.e. −0.059 eV/atom, as listed in Table 2). PP7 is calculated by dividing the reaction enthalpy between the dilute amount of H₂ and each intermetallic compound by that between the dilute amount of H₂ and Fe. For example, since the reaction enthalpy between the dilute amount of H₂ and CrNi₃ is −0.045, PP7 thus equals −0.045/−0.059, which is about 0.76.

TABLE 4 Information of a first stable decomposition reaction between each intermetallic compound in Table 1 and a dilute amount of H₂. Reaction Intermetallic Equation of a first stable decomposition reaction enthalpy compound PP5 with a dilute amount of H₂ Molar fraction PP6 (eV/atom) PP7 Fe (reference) N/A 0.333 H₂ + 0.667 Fe → 0.667 FeH  0.50 1.00 −0.059 1.00 Cr₃Si 0 No Reaction N/A 0.00 N/A 0.00 CrNi₃ 0 0.333 H₂ + 0.667 CrNi₃ → 0.667 NiH + 0.667 CrNi₂  0.50 1.00 −0.045 0.76 CrSi₂ 0 0.87 H₂ + 0.13 CrSi₂ → 0.217 SiH₈ + 0.043 Cr₃Si  6.69 0.07 −0.066 1.12 Fe₂Mo 0 0.5 H₂ + 0.5 Fe₂Mo → FeH + 0.5 Mo  1.00 0.50 −0.047 0.80 Fe₃Si 0 0.846 H₂ + 0.154 Fe₃Si → 0.154 SiH₈ + 0.462 FeH  5.49 0.09 −0.009 0.15 FeNi 0 0.5 H₂ + 0.5 FeNi → 0.5 FeH + 0.5 NiH  1.00 0.50 −0.051 0.86 FeNi₃ 0 0.5 H₂ + 0.5 FeNi₃ → 0.5 FeNi + NiH  1.00 0.50 −0.039 0.66 FeSi 0 0.727 H₂ + 0.273 FeSi → 0.182 SiH₈ + 0.091 Fe₃Si  2.66 0.19 −0.013 0.22 FeSi₂ 0 0.8 H₂ + 0.2 FeSi₂→ 0.2 SiH₈ + 0.2 FeSi  4.00 0.13 −0.067 1.14 Mn₃Si 0 No Reaction N/A 0.00 N/A 0.00 Mn₄Si₇ 0 0.923 H₂ + 0.077 Mn₄Si₇ → 0.231 SiH₈ + 0.308 11.99 0.04 −0.060 1.02 MnSi MnNi₃ 0 0.605 H₂ + 0.395 MnNi₃ → 1.184 NiH + 0.014  1.53 0.33 −0.036 0.61 Mn2₉H₂   MnSi 0 0.727 H₂ + 0.273 MnSi → 0.182 SiH₈ + 0.091  2.66 0.19 −0.026 0.44 Mn₃Si   Ni₃Mo 0 0.6 H₂ + 0.4 Ni₃Mo → 0.4 Mo + 1.2 NiH  1.50 0.33 −0.044 0.75 Ni₄Mo 0 0.333 H₂ + 0.667 NiMo → 0.667 Ni₃Mo + 0.667  0.50 1.00 −0.031 0.53 NIH   Si₁₂Ni₃₁ 0 0.778 H₂ + 0.222 Si1₂Ni3₁ → 1.556 NiH + 2.667  3.50 0.14 −0.005 0.08 SiNi₂   Si₂Mo 0 0.848 H₂ + 0.152 Si₂Mo → 0.212 SiH₈ + 0.03  5.58 0.09 −0.043 0.73 Si₃Mo₅   Si₂Ni 0 0.8 H₂ + 0.2 Si₂Ni → 0.2 SiH₈ + 0.2 SiNi  4.00 0.13 −0.088 1.49 Si₃Mo₅ 0 0.842 H₂ + 0.158 Si₃Mo₅ → 0.211 SiH₈ + 0.263  5.33 0.09 −0.013 0.22 SiMo₃ SiMo3 0 No Reaction N/A 0.00 N/A 0.00 SiNi 0 0.667 H₂ + 0.333 SiNi → 0.167 SiH₈ + 0.167  2.00 0.25 −0.062 1.05 SiNi₂ SiNi₂ 0 No Reaction N/A 0.00 N/A 0.00 SiNi₃ 0 0.172 H₂ + 0.828 SiNi₃ → 0.069 Si1₂Ni3₁ + 0.345  0.21 2.41 −0.006 0.10 NiH   Fe₇Mo₆ 1 0.778 H₂ + 0.222 Fe₇Mo₆ → 1.556 FeH + 1.333  3.50 0.14 −0.041 0.69 Mo   Fe₂Si 1 0.571 H₂ + 0.429 Fe₂Si → 0.143 SiH₈ + 0.286  1.33 0.38 −0.011 0.19 Fe₃Si   Mn₃Ni 1 0.084 H₂ + 0.916 Mn₃Ni → 0.305 MnNi₃ + 0.084  0.09 5.45 −0.022 0.37 Mn₂₉H₂   Si₂Ni₃ 1 0.667 H₂ + 0.333 Si₂Ni₃ → 0.167 SiH₈ + 0.5 SiNi₂  2.00 0.25 −0.420 7.12 MnFe3 1 0.033 H₂ + 0.967 MnFe₃ → 2.9 Fe + 0.033 Mn₂₉H₂  0.03 14.65 −0.009 0.15 Fe₁₁Si₅ 1 0.842 H₂ + 0.158 Fe₁₁Si₅ → 0.211 SiH₈ + 0.579  5.33 0.09 −0.018 0.31 Fe₃Si   MnFe 1 0.033 H₂ + 0.967 MnFe → 0.967 Fe + 0.033  0.03 14.65 −0.017 0.29 Mn₂₉H₂   Mn₃Fe 1 0.094 H₂ + 0.906 Mn₃Fe → 0.906 Fe + 0.094  0.10 4.82 −0.025 0.42 Mn₂₉H₂   Fe₅Si₃ 1 0.842 H₂ + 0.158 Fe₅Si₃ → 0.211 SiH₈ + 0.263  5.33 0.09 −0.024 0.41 Fe₃Si   MnCr₃ 2 0.033 H₂ + 0.967 MnCr₃ → 0.033 Mn₂₉H₂ + 2.9 Cr  0.03 14.65 −0.009 0.15 MnNi 2 0.022 H₂ + 0.978 MnNi → 0.326 MnNi₃ + 0.022  0.02 22.23 −0.047 0.80 Mn₂₉H₂   Mn₂FeSi 0 0.647 H₂ + 0.353 Mn₂FeSi → 0.353 FeH + 0.235  1.83 0.27 −0.003 0.05 Mn₃Si + 0.118 SiH₈ Mn₆Si₇Ni₁₆ 0 No Reaction N/A 0.00 N/A 0.00 MnSiNi 0 No Reaction N/A 0.00 N/A 0.00 MnFe₂Si 1 0.786 H₂ + 0.214 MnFe₂Si → 0.429 FeH + 0.071  3.67 0.14 −0.004 0.07 Mn₃Si + 0.143 SiH₈ Mn₂CrSi 1 No Reaction N/A 0.00 N/A 0.00 FeSiMo 1 0.571 H₂ + 0.429 FeSiMo → 0.143 SiMo₃ + 0.143  1.33 0.38 −0.036 0.61 SiH₈ + 0.143 Fe₃Si   MnCrFe₂ 2 0.033 H₂ + 0.967 MnCrFe₂ → 0.967 Cr + 0.033  0.03 14.65 −0.009 0.15 Mn₂₉H₂ + 1.933 Fe Mn₂SiMo 2 No Reaction N/A 0.00 N/A 0.00 MnCrFeSi 2 0.647 H₂ + 0.353 MnCrFeSi → 0.118 SiH₈ +  1.83 0.27 −0.003 0.05 0.118 Mn₃Si + 0.118 Cr₃Si + 0.353 FeH

Table 5 depicts information of the most stable decomposition reaction between each intermetallic compound in Table 1 and an abundant amount of H₂. Particularly, Table 5 provides a reaction equation, if possible, of the most stable decomposition reaction and a reaction enthalpy of each reaction. Table 5 also provides a molar fraction between the abundant amount of H₂ and each intermetallic compound. Further, Table 5 provides a penalty point (e.g. PP8) regarding the molar fraction, where PP8 of 1.00 is assigned to the reference reaction between Fe and the abundant amount of H₂ (i.e. the molar fraction is 0.50, as listed in Table 3). PP8 is calculated by dividing the molar fraction between the abundant amount of H₂ and Fe by the molar fraction between the abundant amount of H₂ and each intermetallic compound. For example, since the molar fraction between the abundant amount of H₂ and CrNi₃ is 2.00, PP8 thus equals 0.50/2.00, which is around 0.25.

Table 5 further provides a reaction enthalpy (eV/atom) of the reaction between the abundant amount of H₂ and each intermetallic compound. Table 5 also provides another penalty point (e.g. PP9) regarding the reaction enthalpy of the reaction, where PP9 of 1.00 is assigned to the reference reaction between Fe and the abundant amount of H₂ (i.e. −0.059 eV/atom, as listed in Table 3). PP9 is calculated by dividing the reaction enthalpy between the abundant amount of H₂ and each intermetallic compound by that between the abundant amount of H₂ and Fe. For example, since the reaction enthalpy between the abundant amount of H₂ and CrNi₃ is −0.089, PP9 thus equals −0.089/−0.059, which is about 1.51.

TABLE 5 Information of the most stable decomposition reaction between each intermetallic compound in Table 1 and an abundant amount of H₂. Reaction Intermetallic Equation of the most stable decomposition Molar enthalpy compound reaction with an abundant amount of H₂ fraction PP8 (eV/atom) PP9 Fe 0.333 H₂ + 0.667 Fe → 0.667 FeH 0.50 1.00 −0.059 1.00 (reference) Cr₃Si No Reaction N/A 0.00 N/A 0.00 CrNi₃ 0.667 H₂ + 0.333 CrNi₃ → 0.333 CrH + NiH 2.00 0.25 −0.089 1.51 CrSi₂ 0.87 H₂ + 0.13 CrSi₂ → 0.217 SiH₈ + 0.043 Cr₃Si 6.69 0.07 −0.066 1.12 Fe₂Mo 0.5 H₂ + 0.5 Fe₂Mo → FeH + 0.5 Mo 1.00 0.50 −0.047 0.80 Fe₃Si 0.846 H₂ + 0.154 Fe₃Si → 0.154 SiH₈ + 0.462 FeH 5.49 0.09 −0.009 0.15 FeNi 0.5 H₂ + 0.5 FeNi → 0.5 FeH + 0.5 NiH 1.00 0.50 −0.051 0.86 FeNi₃ 0.667 H₂ + 0.333 FeNi₃ → 0.333 FeH + NiH 2.00 0.25 −0.055 0.93 FeSi 0.727 H₂ + 0.273 FeSi → 0.182 SiH₈ + 0.091 Fe₃Si 2.66 0.19 −0.013 0.22 FeSi₂ 0.8 H₂ + 0.2 FeSi₂ → 0.2 SiH₈ + 0.2 FeSi 4.00 0.13 −0.067 1.14 Mn₃Si No Reaction N/A 0.00 N/A 0.00 Mn₄Si₇ 0.923 H₂ + 0.077 Mn₄Si₇ → 0.231 SiH₈ + 0.308 MnSi 11.99 0.04 −0.060 1.02 MnNi₃ 0.605 H₂ + 0.395 MnNi₃ → 1.184 NiH + 0.014 Mn₂₉H₂ 1.53 0.33 −0.036 0.61 MnSi 0.727 H₂ + 0.273 MnSi → 0.182 SiH₈ + 0.091 Mn₃Si 2.66 0.19 −0.026 0.44 Ni₃Mo 0.6 H₂ + 0.4 Ni₃Mo → 0.4 Mo + 1.2 NiH 1.50 0.33 −0.044 0.75 Ni₄Mo 0.667 H₂ + 0.333 Ni₄Mo → 0.333 Mo + 1.333 NiH 2.00 0.25 −0.055 0.93 Si₁₂Ni₃₁ 0.778 H₂ + 0.222 Si₁₂Ni₃₁ → 1.556 NiH + 2.667 SiNi₂ 3.50 0.14 −0.005 0.08 Si₂Mo 0.848 H₂ + 0.152 Si₂Mo → 0.212 SiH₈ + 0.03 Si₃Mo₅ 5.58 0.09 −0.043 0.73 Si₂Ni 0.857 H₂ + 0.143 Si₂Ni → 0.214 SiH₈ + 0.071 SiNi₂ 5.99 0.08 −0.089 1.51 Si₃Mo₅ 0.842 H₂ + 0.158 Si₃Mo₅ → 0.211 SiH₈ + 0.263 SiMo₃ 5.33 0.09 −0.013 0.22 SiMo₃ No Reaction N/A 0.00 N/A 0.00 SiNi 0.667 H₂ + 0.333 SiNi → 0.167 SiH₈ + 0.167 SiNi₂ 2.00 0.25 −0.062 1.05 SiNi₂ No Reaction N/A 0.00 N/A 0.00 SiNi₃ 0.333 H₂ + 0.667 SiNi₃ → 0.667 NiH + 0.667 SiNi₂ 0.50 1.00 −0.010 0.17 Fe₇Mo₆ 0.778 H₂ + 0.222 Fe₇Mo₆ → 1.556 FeH + 1.333 Mo 3.50 0.14 −0.041 0.69 Fe₂Si 0.833 H₂ + 0.167 Fe₂Si → 0.167 SiH₈ + 0.333 FeH 4.99 0.10 −0.012 0.20 Mn₃Ni 0.376 H₂ + 0.624 Mn₃Ni → 0.624 NiH + 0.065 Mn₂₉H₂ 0.60 0.83 −0.034 0.58 Si₂Ni₃ 0.667 H₂ + 0.333 Si₂Ni₃ → 0.167 SiH₈ + 0.5 SiNi₂ 2.00 0.25 −0.420 7.12 MnFe₃ 0.605 H₂ + 0.395 MnFe₃ → 1.184 FeH + 0.014 Mn₂₉H₂ 1.53 0.33 −0.055 0.93 Fe₁₁Si₅ 0.842 H₂ + 0.158 Fe₁₁Si₅ → 0.211 SiH₈ + 0.579 Fe₃Si 5.33 0.09 −0.018 0.31 MnFe 0.348 H₂ + 0.652 MnFe → 0.652 FeH + 0.022 Mn₂₉H₂ 0.53 0.94 −0.050 0.85 Mn₃Fe 0.376 H₂ + 0.624 Mn₃Fe → 0.624 FeH + 0.065 Mn₂₉H₂ 0.60 0.83 −0.043 0.73 Fe₅Si₃ 0.842 H₂ + 0.158 Fe₅Si₃ → 0.211 SiH₈ + 0.263 Fe₃Si 5.33 0.09 −0.024 0.41 MnCr₃ 0.605 H₂ + 0.395 MnCr₃ → 0.014 Mn₂₉H₂ + 1.184 CrH 1.53 0.33 −0.049 0.83 MnNi 0.348 H₂ + 0.652 MnNi → 0.652 NiH + 0.022 Mn₂₉H₂ 0.53 0.94 −0.060 1.02 Mn₂FeSi 0.647 H₂ + 0.353 Mn₂FeSi → 0.353 FeH + 0.235 Mn₃Si + 1.83 0.27 −0.003 0.05 0.118 SiH₈ Mn₆Si₇Ni₁₆ No Reaction N/A 0.00 N/A 0.00 MnSiNi No Reaction N/A 0.00 N/A 0.00 MnFe₂Si 0.786 H₂ + 0.214 MnFe₂Si → 0.429 FeH + 0.071 Mn₃Si + 3.67 0.14 −0.004 0.07 0.143 SiH₈ Mn₂CrSi No Reaction N/A 0.00 N/A 0.00 FeSiMo 0.571 H₂ + 0.429 FeSiMo → 0.143 SiMo₃ + 0.143 SiH₈ + 1.33 0.38 −0.036 0.61 0.143 Fe₃Si MnCrFe₂ 0.605 H₂ + 0.395 MnCrFe₂ → 0.014 Mn2₉H₂ + 0.395 CrH + 1.53 0.33 −0.053 0.90 0.789 FeH Mn₂SiMo No Reaction N/A 0.00 N/A 0.00 MnCrFeSi 0.647 H₂ + 0.353 MnCrFeSi → 0.118 SiH₈ + 0.118 Mn₃Si + 1.83 0.27 −0.003 0.05 0.118 Cr₃Si + 0.353 FeH

Based on the information provided in Tables 4 and 5, a sum of the penalty points (PPP) is calculated for each intermetallic compound, i.e. ΣPP=PP5+PP6+PP7+PP8+PP9. The sum of penalty points for Fe is 4.00 (i.e. ΣPP_(Fe)=4.00). In one or more embodiments, to find intermetallic compounds that may exhibit comparably better resistance against hydrogen-related degradations (e.g. hydrogen embrittlement) than Fe, ΣPP is less than 4.00. Table 6 depicts a summary of exemplary candidates of intermetallic compounds that may be comparably more resistant to hydrogen-related degradations than Fe. Specifically, Table 6 categorizes the candidates of intermetallic compounds in three categories: (1) those with a ΣPP of less than 1.0 (i.e. ΣPP<1.0); (2) those with a PP of greater than 1.0 but less than 2.0 (i.e. 1.0<ΣPP<2.0); and (3) those with a ΣPP of greater than 2.0 but less than 4.0 (i.e. 2.0<ΣPP<4.0).

TABLE 6 A summary of exemplary candidates of intermetallic compounds that may be comparably more resistant to H₂ than Fe. ΣPP value Intermetallic compounds ΣPP < 1.0 Cr₃Si, Mn₃Si, SiMo₃, SiNi₂, Mn₆Si₇Ni₁₆, MnSiNi, Si₁₂Ni₃₁, Fe₃Si, Si₃Mo₅, Mn₂FeSi, FeSi, Mn₂CrSi 1.0 < ΣPP < 2.0 MnSi, MnFe₂Si, Si₂Mo, Fe₁₁Si₅, Fe₂Si, MnNi₃, Mn₂SiMo, Fe₅Si₃ 2.0 < ΣPP < 4.0 Mn₄Si₇, Ni₃Mo, FeNi₃, CrSi₂, FeSi₂, Fe₂Mo, SiNi, MnCrFeSi, Fe₇Mo₆, Ni₄Mo, FeNi, FeSiMo, Si₂Ni, CrNi₃, SiNi₃ ΣPP_(Fe) = 4.0 Fe (reference)

Results in Table 6 indicate that intermetallic compounds that include elements such as Cr, Mo, or Ni appear to exhibit comparably better resistance against hydrogen-related degradations than Fe. Therefore, increasing the amounts of Cr, Mo, and/or Ni, or triggering the formation of these intermetallic compounds (e.g. by changing element compositions or through heat treatments) within a metal substrate, such as stainless steel, may enhance the resistance of the metal substrate against hydrogen-related degradation.

Table 7 depicts information regarding the reactivities of metal hydrides against H₂. The metal hydrides include NiH, FeH, MnH, CrH, and MoH, which originate from the elements in stainless steel. Among them, NiH, FeH, and MnH are stable at a temperature of around 0 K. CrH is stable at temperatures between around 1 K and up to around 130° C. MoH is stable at temperatures between around 130° C. and up to around 250° C. As shown in Table 7, NiH, FeH, MnH, CrH, and MoH do not react with H₂. The formation of these metal hydrides may not adversely influence the electrical conductivity of stainless steel because they are metallic (i.e. E_(g), bandgap=0 eV). However, the existence of these metal hydrides may make the stainless steel more brittle.

Table 7 also indicates that after forming SiH, SiH may further react with H₂ to form SiH₈. The reaction enthalpy of the reaction is about −0.107 eV/atom. However, because both SiH and SiH₈ are insulating (E_(g), bandgap >2 eV), the formation of either SiH or SiH₈ on stainless steel is not favorable.

TABLE 7 Information regarding the reactivities of metal hydrides against H₂. Reaction Metal Stable when Most stable reaction enthalpy hydrides temperature is with H₂ (eV/atom) NiH At 0 K No reaction N/A FeH No reaction N/A MnH No reaction N/A CrH Between 1 K to 130° C. No reaction N/A SiH 0.778 H₂ + 0.222 SiH → 0.222 SiH₈ −0.107 MoH Between 130 to 250° C. No reaction N/A

Next, the chemical reactivities of binary and ternary carbides against H₂ are discussed. Similarly, the data-driven materials screening method may be used to evaluate the reactivities of carbides against H₂ in order to identify carbides that are comparably resistant to hydrogen-related degradations (e.g. hydrogen embrittlement) and that are suitable to be used as protective coating materials to protect components in electrochemical devices, such as in a fuel cell or electrolyzer system, from hydrogen-related degradations.

Table 8 lists binary and ternary carbides whose reactivities against H₂ are studied using the data-driven materials screening method. Table 8 categorizes the carbides based on their temperature stabilities. For example, binary carbides that are stable at a temperature of around 0 K include Cr₂₃C₆, Cr₇C₃, Mn₂₃C₆, Cr₃C₂, Mo₂C, SiC, and MoC. Binary carbides that are stable at temperatures between around 1 K and up to around 130° C. include Cr₃C, Mn₃C, Mn₅C₂, and Mn₇C₃. Binary carbides that are stable at temperatures between around 130° C. and up to around 250° C. include Fe₂₃C₆. Further, ternary carbides that are stable at a temperature of around 0 K include Ni₆Mo₆C, Ni₂Mo₄C, Mn₃Mo₃C, and Cr₂₁Mo₂C₆. Ternary carbides that are stable at temperatures between around 1 K and up to around 130° C. include Fe₃Mo₃C. Ternary carbides that are stable at temperatures between around 130° C. and up to around 250° C. include Si₃Mo₅C and Mn₅SiC.

TABLE 8 Binary and ternary carbides whose reactivities against H₂ are studied using the data-driven materials screening method. Stable when Category temperature is Compounds Binary At 0 K Cr₂₃C₆, Cr₇C₃, Mn₂₃C₆, Cr₃C₂, Mo₂C, SiC, MoC carbides Between 1 K and 130° C. Cr₃C, Mn₃C, Mn₅C₂, Mn₇C₃ Between 130° C. and 250° C. Fe₂₃C₆ Ternary At 0 K Ni₆Mo₆C, Ni₂Mo₄C, Mn₃Mo₃C, Cr₂₁Mo₂C₆ carbides Between 1 K and 130° C. Fe₃Mo₃C Between 130° C. and 250° C. Si₃Mo₅C, Mn₅SiC

Table 9 depicts information of a first stable decomposition reaction between each carbide in Table 8 and a dilute amount of H₂. Table 9 provides a reaction equation, if possible, of the first stable decomposition reaction and a reaction enthalpy of each reaction. To take the stability of the carbides into consideration, a penalty point (e.g. PP10) is assigned to each carbide. The carbides that are stable at a temperature of around 0 K are assigned a PP10 of 0. Further, the carbides that are stable at temperatures between around 1 K and up to around 130° C. are assigned a PP10 of 1. In addition, the carbides that are stable at temperatures between around 130° C. and up to around 250° C. are assigned a PP10 of 2.

Table 9 also provides a molar fraction between the dilute amount of H₂ and each carbide. Further, Table 9 provides another penalty point (e.g. PP11) regarding the molar fraction, where PP11 of 1.00 is assigned to the reference reaction between Fe and the dilute amount of H₂ (i.e. 0.50, as listed in Table 2). PP11 is calculated by dividing the molar fraction between the dilute amount of H₂ and Fe by the molar fraction between the dilute amount of H₂ and each carbide. For example, since the molar fraction between the dilute amount of H₂ and Cr₂₃C₆ is 11.99, PP11 thus equals 0.50/11.99, which is around 0.04.

Table 9 further provides a reaction enthalpy (eV/atom) of the reaction between the dilute amount of H₂ and each carbide. Table 9 also provides another penalty point (e.g. PP12) regarding the reaction enthalpy of the reaction, where PP12 of 1.00 is assigned to the reference reaction between Fe and the dilute amount of H₂ (i.e. −0.059 eV/atom, as listed in Table 2). PP12 is calculated by dividing the reaction enthalpy between the dilute amount of H₂ and each carbide by that between the dilute amount of H₂ and Fe. For example, since the reaction enthalpy between the dilute amount of H₂ and Cr₂₃C₆ is −0.168, PP12 thus equals −0.168/−0.059, which is about 2.85.

TABLE 9 Information of a first stable decomposition reaction between each carbide in Table 8 and a dilute amount of H₂. Reaction Equation of a first stable decomposition reaction enthalpy Carbides PP10 with a dilute amount of H₂ Molar fraction PP11 (eV/atom) PP12 Fe N/A 0.333 H₂ + 0.667 Fe → 0.667 FeH 0.50 1.00 −0.059 1.00 (reference) Cr₂₃C₆ 0 0.923 H₂ + 0.077 Cr₂₃C₆ → 0.462 H₄C + 1.769 11.99 0.04 −0.168 2.85 Cr Cr₇C₃ 0 0.701 H₂ + 0.299 Cr₇C₃ → 0.091 Cr₂₃C₆ + 0.351 2.34 0.21 −0.123 2.08 H₄C Mn₂₃C₆ 0 0.927 H₂ + 0.072 Mn₂₃C₆ → 0.435 H₄C + 0.057 12.88 0.04 −0.174 2.95 Mn₂₉H₂ Cr₃C 1 0.303 H₂ + 0.697 Cr₃C → 0.091 Cr₂₃C₆ + 0.152 0.43 1.15 −0.080 1.36 H₄C Mn₃C 1 0.303 H₂ + 0.697 Mn₃C → 0.091 Mn₂₃C₆ + 0.152 0.43 1.15 −0.084 1.42 H₄C Cr₃C₂ 0 0.588 H₂ + 0.412 Cr₃C₂ → 0.176 C₇C₃ + 0.294 1.18 0.42 −0.164 2.78 H₄C Mn₅C₂ 1 0.582 H₂ + 0.418 Mn₅C₂ → 0.091 Mn₂₃C₆ + 1.15 0.43 −0.144 2.44 0.291 H₄C Mn₇C₃ 1 0.701 H₂ + 0.299 Mn₇C₃ → 0.091 Mn₂₃C₆ + 2.34 0.21 −0.157 2.66 0.351 H₄C Mo₂C 0 0.667 H₂ + 0.333 Mo₂C → 0.333 H₄C + 0.667 2.00 0.25 −0.225 3.81 Mo Fe₂₃C₆ 2 0.923 H₂ + 0.077 Fe₂₃C₆ → 0.462 H₄C + 1.769 11.99 0.04 −0.213 3.6 Fe SiC 0 0.667 H₂ + 0.333 SiC → 0.333 H₄C + 0.333 Si 2.00 0.25 −0.246 4.17 MoC 0 0.5 H₂ + 0.5 MoC→ 0.25 Mo₂C + 0.25 H₄C 1.00 0.50 −0.237 4.02 Ni₆Mo₆C 0 0.667 H₂ + 0.333 Ni₆Mo₆C → 0.667 Ni₃Mo + 2.00 0.25 −0.088 1.49 0.333 H₄C + 1.333 Mo Ni₂Mo₄C 0 0.571 H₂ + 0.429 Ni₂Mo₄C → 0.143 Ni₆Mo₆C + 1.33 0.38 −0.105 1.78 0.286 H₄C + 0.857 Mo Mn₃Mo₃C 0 0.678 H₂ + 0.322 Mn₃Mo₃C → 0.322 H₄C + 2.11 0.24 −0.130 2.20 0.033 Mn₂₉H₂ + 0.967 Mo Cr₂₁Mo₂C₆ 0 0.923 H₂ + 0.077 Cr₂₁(MoC₃)₂→ 0.462 H₄C + 11.99 0.04 −0.160 2.7 1.615 Cr + 0.154 Mo Fe₃Mo₃C 1 0.667 H₂ + 0.333 Fe₃Mo₃C → 0.333 H₄C + Mo + 2.00 0.25 −0.150 2.54 Fe Si₃Mo₅C 2 0.667 H₂ + 0.333 Si₃Mo₅C → 0.333 H₄C + 0.333 2.00 0.25 −0.145 2.46 Si₃Mo₅ Mn₅SiC 2 0.489 H₂ + 0.511 Mn₅SiC → 0.044 Mn₂₃C₆ + 0.96 0.52 −0.132 2.24 0.244 H₄C + 0.511 Mn₃Si

Table 10 depicts information of the most stable decomposition reaction between each carbide in Table 8 and an abundant amount of H₂. Particularly, Table 10 provides a reaction equation, if possible, of the most stable decomposition reaction and a reaction enthalpy of each reaction. Table 10 also provides a molar fraction between the abundant amount of H₂ and each carbide. Further, Table 10 provides a penalty point (e.g. PP13) regarding the molar fraction, where PP13 of 1.00 is assigned to the reference reaction between Fe and the abundant amount of H₂ (i.e. the molar fraction is 0.50, as listed in Table 3). PP13 is calculated by dividing the molar fraction between the abundant amount of H₂ and Fe by the molar fraction between the abundant amount of H₂ and each carbide. For example, since the molar fraction between the abundant amount of H₂ and Cr₂₃C₆ is 11.99, PP13 thus equals 0.50/11.99, which is around 0.04.

Table 10 further provides a reaction enthalpy (eV/atom) of the reaction between the abundant amount of H₂ and each carbide. Table 10 also provides another penalty point (e.g. PP14) regarding the reaction enthalpy of the reaction, where PP14 of 1.00 is assigned to the reference reaction between Fe and the abundant amount of H₂ (i.e. −0.059 eV/atom, as listed in Table 3). PP14 is calculated by dividing the reaction enthalpy between the abundant amount of H₂ and each carbide by that between the abundant amount of H₂ and Fe. For example, since the reaction enthalpy between the abundant amount of H₂ and Cr₂₃C₆ is −0.168, PP14 thus equals −0.168/−0.059, which is about 2.85.

TABLE 10 Information of the most stable decomposition reaction between each carbide in Table 8 and an abundant amount of H₂. Reaction Equation of the most stable decomposition reaction with an Molar enthalpy Carbides abundant amount of H₂ fraction PP13 (eV/atom) PP14 Fe 0.333 H₂ + 0.667 Fe → 0.667 FeH 0.50 1.00 −0.059 1.00 (reference) Cr₂₃C₆ 0.923 H₂ + 0.077 Cr₂₃C₆ → 0.462 H₄C + 1.769 Cr 11.99 0.04 −0.168 2.85 Cr₇C₃ 0.857 H₂ + 0.143 Cr₇C₃ → 0.429 H₄C + Cr 5.99 0.08 −0.205 3.47 Mn₂₃C₆ 0.927 H₂ + 0.072 Mn₂₃C₆ → 0.435 H₄C + 0.057 Mn₉H₂ 12.88 0.04 −0.174 2.95 Cr₃C 0.667 H₂ + 0.333 Cr₃C → 0.333 H₄C + Cr 2.00 0.25 −0.194 3.29 Mn₃C 0.678 H₂ + 0.322 Mn₃C → 0.322 H₄C + 0.033 Mn₂₉H₂ 2.11 0.24 −0.201 3.41 Cr₃C₂ 0.8 H₂+ 0.2 Cr₃C₂ → 0.4 H₄C + 0.6 Cr 4.00 0.13 −0.248 4.20 Mn₅C₂ 0.807 H₂ + 0.193 Mn₅C₂ → 0.387 H₄C + 0.033 Mn₂₉H₂ 4.18 0.12 −0.226 3.83 Mn₇C₃ 0.862 H₂ + 0.138 Mn₇C₃ → 0.414 H₄C + 0.033 Mn₂₉H₂ 6.25 0.08 −0.231 3.92 Mo₂C 0.667 H₂ + 0.333 Mo₂C → 0.333 H₄C + 0.667 Mo 2.00 0.25 −0.225 3.81 Fe₂₃C₆ 0.959 H₂ + 0.041 Fe2₃C₆ → 0.939 FeH + 0.245 H₄C 23.39 0.02 −0.185 3.14 SiC 0.667 H₂ + 0.333 SiC → 0.333 H₄C + 0.333 Si 2.00 0.25 −0.246 4.17 MoC 0.667 H₂ + 0.333 MoC → 0.333 H₄C + 0.333 Mo 2.00 0.25 −0.289 4.90 Ni₆Mo₆C 0.833 H₂ + 0.167 Ni₆Mo₆C → 0.167 H₄C + NiH + Mo 4.99 0.10 −0.092 1.56 Ni₂Mo₄C 0.667 H₂ + 0.333 Ni₂Mo₄C → 0.222 Ni₃Mo + 0.333 H₄C + 2.00 0.25 −0.138 2.34 1.111 Mo Mn₃Mo₃C 0.678 H₂ + 0.322 Mn₃Mo₃C → 0.322 H₄C + 0.033 Mn₉H₂ + 2.11 0.24 −0.130 2.20 0.967 Mo Cr₂₁Mo₂C₆ 0.923 H₂ + 0.077 Cr₂₁(MoC₃)₂ → 0.462 H₄C + 1.615 Cr + 11.99 0.04 −0.160 2.71 0.154 Mo Fe₃Mo₃C 0.667 H₂ + 0.333 Fe₃Mo₃C → 0.333 H₄C + Mo + Fe 2.00 0.25 −0.150 2.54 Si₃Mo₅C 0.667 H₂ + 0.333 Si₃Mo₅C → 0.333 H₄C + 0.333 Si₃Mo₅ 2.00 0.25 −0.145 2.46 Mn₅SiC 0.674 H₂ + 0.326 Mn₅SiC → 0.022 Mn₂₉H₂ + 0.326 H₄C + 2.07 0.24 −0.180 3.05 0.326 Mn₃Si

Based on the information provided in Tables 9 and 10, a sum of the penalty points (ΣPP′) is calculated for each carbide, i.e. ΣPP′=PP10+PP11+PP12+PP13+PP14. The sum of penalty points for Fe is 4.00 (i.e. ΣPP_(Fe)=4.00). Table 11 provides a summary of exemplary candidates of carbides that may exhibit comparably better resistance to Hz when compared to Fe. Table 11 provides the molecular weight (MW) of each carbide, a sum of penalty points (ΣPP′) for each carbide, and a sum of penalty points of each carbide per MW (ΣPP′ per MW). As shown in Table 11, the sum of penalty points of Fe per MW is about 71.62 per mg. The candidates of carbides listed in Table 11 all have a ΣPP′ per MVW lower than that of Fe.

TABLE 11 A summary of exemplary candidates of carbides that may exhibit comparably better resistance to H₂ when compared to Fe. MW ΣPP′ per MW Compounds (g/mol) ΣPP′ (mg) Fe 55.85 4.00 71.62 (reference) Ni₆Mo₆C 939.81 3.40 3.62 Cr₂₁Mo₂C₆ 1355.86 5.51 4.06 Mn₂₃C₆ 1335.64 5.98 4.47 Cr₂₃C₆ 1267.97 5.78 4.56 Fe₂₃C₆ 1356.50 8.81 6.49 Ni₂Mo₄C 513.16 4.74 9.25 Mn₃Mo₃C 464.64 4.88 10.51 Si₃Mo₅C 575.97 7.42 12.87 Fe₃Mo₃C 467.37 6.58 14.09 Cr₇C₃ 400.00 5.86 14.64 Mn₇C₃ 420.60 7.87 18.71 Mn₅SiC 314.79 8.05 25.58 Mn₅C₂ 298.71 7.82 26.19 Mo₂C 203.89 8.13 39.86 Mn₃C 176.82 7.22 40.82 Cr₃C₂ 180.01 7.53 41.83 Cr₃C 168.00 7.04 41.93

Apart from intermetallic compounds and carbides, MAX phase compounds may also exhibit resistance against H₂ and be suitable to be used as protective coating materials to protect components in electrochemical devices, such as in a fuel cell or electrolyzer system, from hydrogen-related degradations (e.g. hydrogen embrittlement). MAX phase compounds are layered hexagonal carbides or nitrides with a general formula of M_(n+1)AX_(n), where n=1 to 4, M is an early transition metal, A is an A-group element (e.g. IIIA, IVA, group 13, or group 14 element), and X is either C or N.

The reactivities of MAX phase compounds against H₂ may be evaluated using the data-driven materials screening method. Non-limiting examples of MAX phase compounds whose reactivities against H₂ are examined using the data-driven materials screening method include Zr₂SnC, Nb₂SnC, Ti₃SnC₂, V₂PC, Nb₂AlC, Nb₂PC, Ti₃AlC₂, Ti₃SiC₂, Ti₂SnC, Zr₂SC, Ti₂SC, Nb₄AlC₃, and Ti₄AlN₃.

Table 12 depicts information of a first stable decomposition reaction between each MAX phase compound and a dilute amount of H₂. Table 12 provides a reaction equation, if possible, of the first stable decomposition reaction and a reaction enthalpy of each reaction. Table 12 also provides a molar fraction between the dilute amount of H₂ and each MAX phase compound. Further, Table 12 provides a penalty point (e.g. PP15) regarding the molar fraction, where PP15 of 1.00 is assigned to the reference reaction between Fe and the dilute amount of H₂ (i.e. 0.50, as listed in Table 2). PP15 is calculated by dividing the molar fraction between the dilute amount of H₂ and Fe by the molar fraction between the dilute amount of H₂ and each MAX phase compound. For example, since the molar fraction between the dilute amount of H₂ and Zr₂SnC is 4.00, PP11 thus equals 0.50/4.00, which is around 0.13.

Table 12 further provides a reaction enthalpy (eV/atom) of the reaction between the dilute amount of H₂ and each MAX phase compound. Table 12 also provides another penalty point (e.g. PP16) regarding the reaction enthalpy of the reaction, where PP16 of 1.00 is assigned to the reference reaction between Fe and the dilute amount of H₂ (i.e. −0.059 eV/atom, as listed in Table 2). PP16 is calculated by dividing the reaction enthalpy between the dilute amount of H₂ and each MAX phase compound by that between the dilute amount of H₂ and Fe. For example, since the reaction enthalpy between the dilute amount of H₂ and Zr₂SnC is −0.222, PP15 thus equals −0.222/−0.059, which is about 3.76.

TABLE 12 Information of a first stable decomposition reaction between each MAX phase compound and a dilute amount of H₂. MAX Reaction phase Equation of a first stable decomposition Molar enthalpy compound reaction with a dilute amount of H₂ fraction PP15 (eV/atom) PP16 Fe 0.333 H₂ + 0.667 Fe → 0.667 FeH 0.50 1.00 −0.059 1.00 (reference) Zr₂SnC 0.8 H₂ + 0.2 Zr₂SnC → 0.4 ZrH₂ + 0.2 H₄C + 0.2 Sn 4.00 0.13 −0.222 3.76 Nb₂SnC 0.8 H₂ + 0.2 Nb₂SnC → 0.4 NbH₂ + 0.2 H₄C + 0.2 Sn 4.00 0.13 −0.180 3.05 Ti₃SnC₂ 0.875 H₂ + 0.125 Ti₃SnC₂ → 0.375 TiH₂ + 0.25 H₄C + 7.00 0.07 −0.217 3.68 0.125 Sn V₂PC 0.5 H₂ + 0.5 V₂PC → 0.25 V₄P₂C + 0.25 H₄C 1.00 0.50 −0.150 2.54 Nb₂AlC 0.786 H₂ + 0.214 Nb₂AlC → 0.214 H₄C + 0.071 NbAl₃ + 3.67 0.14 −0.181 3.07 0.357 NbH₂ Nb₂PC 0.25 H₂ + 0.75 Nb₂PC → 0.125 H₄C + 0.125 Nb₆C₅ + 0.33 1.50 −0.063 1.07 0.75 NbP Ti₃AlC₂ 0.87 H₂ + 0.13 Ti₃AlC₂ → 0.043 TiAl₃ + 0.348 TiH₂ + 6.69 0.07 −0.227 3.85 0.261 H₄C Ti₃SiC₂ 0.857 H₂ + 0.143 Ti₃SiC₂ → 0.286 H₄C + 0.143 TiSi + 5.99 0.08 −0.216 3.66 0.286 TiH₂ Ti₂SnC 0.333 H₂ + 0.667 Ti₂SnC → 0.333 Ti₃SnC₂ + 0.333 TiH₂ + 0.50 1.00 −0.067 1.14 0.333 Sn Zr₂SC 0.765 H₂ + 0.235 Zr₂CS → 0.235 H₄C + 0.294 ZrH₂ + 3.26 0.15 −0.165 2.80 0.059 Zr₃S₄ Ti₂SC 0.75 H₂ + 0.25 Ti₂CS → 0.25 H₄C + 0.25 TiH₂ + 3.00 0.17 −0.157 2.66 0.25 TiS Nb₄AlC₃ 0.25 H₂ + 0.75 Nb₄AlC₃ → 0.75 Nb₃AlC₂ + 0.125 Nb₆C₅ + 0.33 1.50 −0.035 0.59 0.125 H₄C Ti₄AlN₃ 0.667 H₂ + 0.333 Ti₄AlN₃ → 0.667 TiH₂ + 0.333 AlN + 2.00 0.25 −0.123 2.08 0.667 TiN

Table 13 depicts information of the most stable decomposition reaction between each MAX phase compound and an abundant amount of H₂. Particularly, Table 13 provides a reaction equation, if possible, of the most stable decomposition reaction and a reaction enthalpy of each reaction. Table 13 also provides a molar fraction between the abundant amount of H₂ and each MAX phase compound. Further, Table 13 provides a penalty point (e.g. PP17) regarding the molar fraction, where PP17 of 1.00 is assigned to the reference reaction between Fe and the abundant amount of H₂ (i.e. the molar fraction is 0.50, as listed in Table 3). PP17 is calculated by dividing the molar fraction between the abundant amount of H₂ and Fe by the molar fraction between the abundant amount of H₂ and each MAX phase compound. For example, since the molar fraction between the abundant amount of H₂ and Zr₂SnC is 4.00, PP17 thus equals 0.50/4.00, which is around 0.13.

Table 13 further provides a reaction enthalpy (eV/atom) of the reaction between the abundant amount of H₂ and each MAX phase compound. Table 13 also provides another penalty point (e.g. PP18) regarding the reaction enthalpy of the reaction, where PP18 of 1.00 is assigned to the reference reaction between Fe and the abundant amount of H₂ (i.e. −0.059 eV/atom, as listed in Table 3). PP18 is calculated by dividing the reaction enthalpy between the abundant amount of H₂ and each MAX phase compound by that between the abundant amount of H₂ and Fe. For example, since the reaction enthalpy between the abundant amount of H₂ and Zr₂SnC is −0.222, PP18 thus equals −0.222/−0.059, which is about 3.76.

TABLE 13 Information of the most stable decomposition reaction between each MAX phase compound and an abundant amount of H₂. MAX Reaction phase Equation of the most stable decomposition reaction with Molar enthalpy compound an abundant amount of H₂ fraction PP17 (eV/atom) PP18 Fe 0.333 H₂ + 0.667 Fe → 0.667 FeH 0.50 1.00 −0.059 1.00 (reference) Zr₂SnC 0.8 H₂ + 0.2 Zr₂SnC → 0.4 ZrH₂ + 0.2 H₄C + 0.2 Sn 4.00 0.13 −0.222 3.76 Nb₂SnC 0.8 H₂ + 0.2 Nb₂SnC → 0.4 NbH₂ + 0.2 H₄C + 0.2 Sn 4.00 0.13 −0.180 3.05 Ti₃SnC₂ 0.875 H₂ + 0.125 Ti₃SnC₂ → 0.375 TiH₂ + 0.25 H₄C + 7.00 0.07 −0.217 3.68 0.125 Sn V₂PC 0.696 H₂ + 0.304 V₂PC → 0.043 V1₂P₇ + 0.087 VH₂ + 2.29 0.22 −0.195 3.31 0.304 H₄C Nb₂AlC 0.786 H₂ + 0.214 Nb₂AlC → 0.214 H₄C + 0.071 NbAl₃ + 3.67 0.14 −0.181 3.07 0.357 NbH₂ Nb₂PC 0.75 H₂ + 0.25 Nb₂PC → 0.25 H₄C + 0.25 NbH₂ + 3.00 0.17 −0.183 3.10 0.25 NbP Ti₃AlC₂ 0.87 H₂ + 0.13 Ti₃AlC₂ → 0.043 TiAl₃ + 0.348 TiH₂ + 6.69 0.07 −0.227 3.85 0.261 H₄C Ti₃SiC₂ 0.857 H₂ + 0.143 Ti₃SiC₂ → 0.286 H₄C + 0.143 TiSi + 5.99 0.08 −0.216 3.66 0.286 TiH₂ Ti₂SnC 0.8 H₂ + 0.2 Ti₂SnC → 0.4 TiH₂ + 0.2 H₄C + 0.2 Sn 4.00 0.13 −0.209 3.54 Zr₂SC 0.765 H₂ + 0.235 Zr₂CS → 0.235 H₄C + 0.294 ZrH₂ + 3.26 0.15 −0.165 2.80 0.059 Zr₃S₄ Ti₂SC 0.75 H₂ + 0.25 Ti₂CS → 0.25 H₄C + 0.25 TiH₂ + 0.25 TiS 3.00 0.17 −0.157 2.66 Nb₄AlC₃ 0.906 H₂ + 0.094 Nb₄AlC₃ → 0.281 H₄C + 0.031 NbAl₃ + 9.64 0.05 −0.205 3.47 0.344 NbH₂ Ti₄AlN₃ 0.667 H₂ + 0.333 Ti₄AlN₃ → 0.667 TiH₂ + 0.333 AlN + 2.00 0.25 −0.123 2.08 0.667 TiN

Based on the information provided in Tables 12 and 13, a sum of the penalty points (ΣPP″) is calculated for each MAX phase compound, i.e. ΣPP″=PP15+PP16+PP17+PP18. The sum of penalty points for Fe is 4.00 (i.e. ΣPP_(Fe)=4.00). Table 14 provides a summary of exemplary candidates of MAX phase compounds that may exhibit comparably better resistance against Hz when compared to Fe. Table 14 also provides a sum of penalty points (ΣPP″) of each MAX phase compound.

Table 14 further provides the molecular weight (MW) of each MAX phase compound, a sum of penalty points of each MAX phase compound per MW (ΣPP″ per MW), and a percentage of improvement of each MAX phase compound when compared to Fe based on the ΣPP″ per MW. It is noted that ΣPP_(Fe) per MW is around 0.072. To calculate the percentage of improvement of each MAX phase compound when compared to Fe based on the ΣPP″ per MW, ΣPP_(Fe) per MW is divided by the ΣPP″ per MW of each MAX phase compound. For example, since the ΣPP″ per MW for Nb₄AlC₃ is around 0.013, the percentage of improvement of Nb₄AlC₃ when compared to Fe thus equals 0.072/0.013, which is around 554.0%.

Table 14 also provides the density of each MAX phase compound, a sum of penalty points of each MAX phase compound per volume (ΣPP″ per volume), and a percentage of improvement of each MAX phase compound when compared to Fe based on the ΣPP″ per volume. ΣPP_(Fe) per volume equals (ΣPP_(Fe) per MW)*(the density of Fe), i.e. 0.072*8.03, which is around 0.575. To calculate the percentage of improvement of each MAX phase compound when compared to Fe based on the ΣPP″ per volume, ΣPP_(Fe) per volume is divided by the ΣPP″ per volume of each MAX phase compound. For example, since the ΣPP″ per volume for Nb₄AlC₃ is around 0.089, the percentage of improvement of Nb₄AlC₃ when compared to Fe thus equals 0.575/0.089, which is around 649.3%.

In addition, Table 14 provides a total percentage of improvement of each MAX phase compound when compared to Fe, which represents a sum of the percentage of improvement of each MAX phase compound when compared to Fe based on the ΣPP″ per MW plus the percentage of improvement of each MAX phase compound when compared to Fe based on the ΣPP″ per volume. For comparison, the percentage of improvement of Fe based on ΣPP_(Fe) per MW is assigned as 100%, and the percentage of improvement of Fe based on ΣPP_(Fe) per volume is also assigned as 100%. As shown in Table 14, all the MAX phase compounds exhibit a total percentage of improvement greater than 100%. This indicates that the MAX phase compounds in Table 14 may exhibit comparably better resistance against H₂ when compared to Fe, thus suitable to be used as protective coating materials to protect metal components from hydrogen-related degradations (e.g. hydrogen embrittlement).

TABLE 14 A summary of exemplary candidates of MAX phase compounds that may exhibit comparably better resistance against H₂ when compared to Fe. MAX MW Density ΣPP″ per ΣPP″ per % of improvement % of improvement Total % of Phase (g/mol) (g/cm³) ΣPP″ MW (g) volume (cm³) per MW (g) per volume (cm³) improvement Fe (reference)  55.85 8.03 4.000 0.072 0.575 100.0% 100.0%  200.0% Nb₄AlC₃ 434.64 6.85 5.620 0.013 0.089 554.0% 649.3% 1203.3% Ti₄AlN₃ 260.47 4.74 4.669 0.018 0.085 399.5% 676.7% 1076.2% Nb₂SnC 316.53 8.13 6.352 0.020 0.163 356.9% 352.6%  709.5% Ti₃SnC₂ 286.33 5.91 7.499 0.026 0.155 273.5% 371.7%  645.2% Zr₂SC 226.52 6.01 5.900 0.026 0.157 275.0% 367.1%  642.0% Ti₂SnC 226.45 6.25 5.803 0.026 0.160 279.5% 359.3%  638.8% Zr₂SnC 313.17 7.12 7.775 0.025 0.177 288.5% 325.1%  613.6% Nb₂PC 228.80 6.87 5.836 0.026 0.175 280.8% 328.0%  608.8% Nb₂AlC 224.81 6.30 6.408 0.029 0.179 251.3% 320.5%  571.8% Ti₃SiC₂ 195.71 4.48 7.489 0.038 0.171 187.2% 335.8%  523.0% Ti₃AlC₂ 194.60 4.21 7.844 0.040 0.170 177.7% 339.0%  516.7% Ti₂SC 139.81 4.64 5.655 0.040 0.187 177.1% 306.7%  483.8% V₂PC 144.87 5.40 6.566 0.045 0.245 158.0% 235.2%  393.2%

In view of Tables 6, 11, and 14, there may be several methods to protect a metal substrate, such as steel or stainless steel, especially metal components in electrochemical devices, such as in a fuel cell or electrolyzer system, which are generally made of metal substrates, from hydrogen-related degradations (e.g. hydrogen embrittlement).

In a first method, to increase the resistance of metal substrate against hydrogen-related degradations (e.g. hydrogen embrittlement), the amounts of Cr, Mo, and/or Ni in the metal substrate may be increased to achieve a target resistance capability.

In a second method, to increase the resistance of metal substrate against hydrogen-related degradations (e.g. hydrogen embrittlement), the metal substrate may include microstructures containing intermetallic compounds therewithin. The intermetallic compounds may be formed within the metal substrates by, for example, changing element compositions or through heat treatments. The metal substrate may include a surface region and a bulk region. Microstructures containing intermetallic compounds may precipitate at or near grain boundaries in the metal substrate or may segregate toward the surface region of the metal substrate or stay in the bulk region of the metal substrate. The intermetallic compounds may be, but not limited to, Cr₃Si, Mn₃Si, SiMo₃, SiNi₂, Mn₆Si₇Ni₁₆, MnSiNi, Si₁₂Ni₃₁, Fe₃Si, Si₃Mo₅, Mn₂FeSi, FeSi, Mn₂CrSi, MnSi, MnFe₂Si, Si₂Mo, Fe₁₁Si₅, Fe₂Si, MnNi₃, Mn₂SiMo, Fe₅Si₃, Mn₄Si₇, Ni₃Mo, FeNi₃, CrSi₂, FeSi₂, Fe₂Mo, SiNi, MnCrFeSi, Fe₇Mo₆, Ni₄Mo, FeNi, FeSiMo, Si₂Ni, CrNi₃, SiNi₃, or a combination thereof. Metal dopants, such as aluminum (Al), magnesium (Mg), zinc (Zn), titanium (Ti), or copper (Cu), may be added into the metal substrates to further enhance the resistance of the metal substrates against hydrogen-related degradation.

In a third method, to increase the resistance of metal substrate against hydrogen-related degradations (e.g. hydrogen embrittlement), at least one surface coating layer of a protective coating material may be applied to at least one surface (i.e. an outer surface) of the metal substrate. The protective coating material may be a carbide material. The carbide material is a carbide compound, including, but not limited to, Ni₆Mo₆C, Cr₂₁Mo₂C₆, Mn₂₃C₆, Cr₂₃C₆, Fe₂₃C₆, Ni₂Mo₄C, Mn₃Mo₃C, Si₃Mo₅C, Fe₃Mo₃C, Cr₇C₃, Mn₇C₃, Mn₅SiC, Mn₅C₂, Mo₂C, Mn₃C, Cr₃C₂, Cr₃C, or a combination thereof. The protective coating material may also be a MAX phase material. The MAX phase material is a MAX phase compound with a general formula of M_(n+1)AX_(n), where n=1 to 4, M is an early transition metal, A is an A-group element (e.g. IIIA, IVA, group 13, or group 14 element), and X is either C or N. The MAX phase compound may include, but not limited to, Nb₄AlC₃, Ti₄AlN₃, Nb₂SnC, Ti₃SnC₂, Zr₂SC, Ti₂SnC, Zr₂SnC, Nb₂PC, Nb₂AlC, Ti₃SiC₂, Ti₃AlC₂, Ti₂SC, V₂PC, or a combination thereof. Upon disposition of a MAX phase coating material onto the at least one surface of the metal substrate, the MAX phase coating material may form stable interfaces with oxides species (e.g. chromium oxide (Cr₂₀₃), iron oxide (Fe₂O₃), or nickel oxide (NiO)) that are present at the surface of the metal substrate.

Still referring to the third method, metal dopants, such as Al, Mg, Zn, Ti, or Cu, may be added into the metal substrate to further enhance the resistance of the metal substrate against hydrogen-related degradations. The protective coating material may also be mixed with other conductive and anti-corrosive compounds, including, but not limited to, nitrides (e.g. chromium nitride (CrN_(x), 0.5≤x≤2), aluminum nitride (AlN), or titanium nitride (TiN_(x), 0.3≤x≤2)), carbides, and/or oxides (e.g. titanium oxide (TiO_(x), 0.5≤x≤2), niobium oxide (NbO_(x), 1≤x≤3), or magnesium titanium oxide (MgTi₂O_(5-x), 0≤x≤5)) to enhance the conductivity and/or the anti-corrosion resistance of the metal substrate. By applying a protective coating material to the metal substrate may reduce the cost of manufacturing the metal substrate.

The MAX phase compounds may be prepared via a solid-state method, a solution precipitation-based method, or a sol-gel process. Specifically, for nitride-based MAX phase compounds, solid-state precursors of A_(x)B_(y)O_(z) (A and B are metal elements) may be treated with N₂, NH₃, or both, at temperatures varying from about 250 to 2,000° C. to yield a ternary nitride compound, A_(x)B_(y)N_(z). For carbide-based MAX phase compounds, metal elements or metal hydrides may be mixed with carbon powders. The resulting powders may be pelletized and heat-treated at temperatures varying from about 400 to 2,000° C. to yield a ternary carbide compound A_(x)B_(y)C_(z). For the solution precipitation-based method, two different metallic complexes (e.g. metal chlorides, metal nitrates, or metal sulfates) may be dissolved in a solvent (e.g. water, acetonitrile, acetone, ethanol, or isopropyl alcohol), followed by adding another chemical molecule, such as ethanolamine, to the reaction mixture to yield a precipitate. The resulting reaction mixture may be filtered and dried and heated in a reducing environment (e.g. under N₂ or NH₃) to afford a ternary MAX phase compound. For the sol-gel process, metal alkoxides may be used as a precursor to prepare a MAX phase compounds.

To deposit a protective coating layer of a MAX phase material to the at least one surface of the metal substrate, several techniques may be employed. For example, physical vapor deposition (PVD) is one of the most widely used techniques for the deposition of MAX phase thin films onto a substrate, including a metal substrate. Depending on the composition of a MAX phase compound, different variations of PVD, including magnetron sputtering, high-power impulse magnetron sputtering (HiPIMS), or pulsed laser deposition, may be used. Temperatures varying from about 400° C. to 1,100° C. may be required for the deposition. In addition, chemical vapor deposition techniques (CVD), such as atomic layer deposition, plasma-enhanced CVD or laser CVD, may also be used to deposit MAX phase thin films onto the substrate. Further, electrospun precursor fibers containing target metals may be thermally treated, where the addition of organic molecules, such as methylated polyuria, may help control the morphology of the defined fibers. Viscous solutions including the target metals may be dried into a glass or glassy film, and a processing step, such as spray coating, spinning, printing, or templating, can be used to deposit the precursor onto the substrate.

An interfacial contact resistance between a protective coating layer and a metal substrate may be less than 50 Ohm cm², and in other embodiments, less than 0.01 Ohm cm² during a normal operation of an electrochemical device. An electrical conductivity value of the protective coating layer may be at least 0.1 S cm⁻¹, and in other embodiments, greater than 100 S cm⁻¹. Each protective coating layer may have a thickness of 5 nm to 1 mm, typically in a range of 50 nm and 500 μm, depending on a target conductivity.

Next, exemplary embodiments will be discussed in a fuel cell system. It is noted that the protection methods applied to the fuel cell system as described herein may also be applicable to metal components in other electrochemical devices, such as metal components in an electrolyzer system.

FIG. 5A is a schematic cross-sectional view of a fuel cell. FIG. 5B is a schematic perspective view of components of the fuel cell shown in FIG. 5A. FIG. 5A also generally depicts the reactants and products of the operation of the fuel cell. The fuel cell 30 may be a proton-exchange membrane (PEM) fuel cell. As shown in FIG. 5A, the fuel cell 30 includes a PEM 32, a first catalyst layer 34 and a second catalyst layer 36. The PEM 32 is situated between the first and second catalyst layers, 34 and 36. The fuel cell 30 further includes a first gas diffusion layer (GDL) 38 surrounds the first catalyst layer 34, and a second GDL 40 surrounds the second catalyst layer 36. The fuel cell 30 also includes a first bipolar plate 42 and a second bipolar plate 44. The first and second bipolar plates, 42 and 44, are positioned at opposite ends of the fuel cell 30 and surround the first and second GDLs, 38 and 40, respectively. The first and second bipolar plates, 42 and 44, are typically formed of a metal substrate, such as steel or stainless steel, and have at least one surface.

The first and second bipolar plates, 42 and 44, may provide structural support and conductivity, and may assist in supplying fuel and oxidants (air) in the fuel cell 30. The first and second bipolar plates, 42 and 44, may also assist in removal of reaction products or byproducts from the fuel cell 30. As shown in FIG. 5B, the first bipolar plate 42 includes a flow passage 46. The second bipolar plate 44 also includes a flow passage (not shown). The flow passages are configured to assist in supplying fuel and/or removing by-products in the fuel cell 30.

Apart from the components within the fuel cell 30, to properly function, the fuel cell 30 is connected to other components in the fuel cell system. These other components may include, but not limited to, fuel storage tanks, connecting pipes, safety valves, condensers, or heat exchangers. These other components, like bipolar plates, may also be made of metal-based materials, such as steel or stainless steel, and may also be exposed to H₂ gas and subjected to hydrogen-related degradations (e.g. hydrogen embrittlement). Therefore, to maintain a healthy environment in the fuel cell system and extend the durability of the fuel cell, these other components as well as bipolar plates are needed to be protected from potential hydrogen-related degradations.

In one embodiment, to protect the component in the fuel cell system from hydrogen-related degradations (e.g. hydrogen embrittlement), the component may be made of a metal substrate (e.g. steel or stainless steel) having a high amount of Cr, Mo, and/or Ni elements.

In another embodiment, to protect the component in the fuel cell system from hydrogen-related degradations (e.g. hydrogen embrittlement), the component made of stainless steel may include microstructures containing intermetallic compounds therewithin. The intermetallic compounds may be formed within the component by, for example, changing element compositions or through heat treatments. The component may include a surface region and a bulk region. Microstructures containing intermetallic compounds may precipitate at or near grain boundaries in the component or may segregate toward the surface region of the component or stay in the bulk region of the component. The intermetallic compounds may be, but not limited to, Cr₃Si, Mn₃Si, SiMo₃, SiNi₂, Mn₆Si₇Ni₁₆, MnSiNi, Si₁₂Ni₃₁, Fe₃Si, Si₃Mo₅, Mn₂FeSi, FeSi, Mn₂CrSi, MnSi, MnFe₂Si, Si₂Mo, Fe₁₁Si₅, Fe₂Si, MnNi₃, Mn₂SiMo, Fe₅Si₃, Mn₄Si₇, Ni₃Mo, FeNi₃, CrSi₂, FeSi₂, Fe₂Mo, SiNi, MnCrFeSi, Fe₇Mo₆, Ni₄Mo, FeNi, FeSiMo, Si₂Ni, CrNi₃, SiNi₃, or a combination thereof. Metal dopants, such as Al, Mg, Zn, Ti, or Cu, may be added into the component to further enhance the resistance of the component against hydrogen-related degradations.

In yet another embodiment, to protect the component in the fuel cell system from hydrogen-related degradations (e.g. hydrogen embrittlement), at least one surface coating layer of a protecting coating material may be applied to at least one surface of the component. The protective coating material may be a carbide material. The carbide material is a carbide compound, including, but not limited to, Ni₆Mo₆C, Cr₂₁Mo₂C₆, Mn₂₃C₆, Cr₂₃C₆, Fe₂₃C₆, Ni₂Mo₄C, Mn₃Mo₃C, Si₃Mo₅C, Fe₃Mo₃C, Cr₇C₃, Mn₇C₃, Mn₅SiC, Mn₅C₂, Mo₂C, Mn₃C, Cr₃C₂, Cr₃C, or a combination thereof. The protective coating material may also be a MAX phase material. The MAX phase material is a MAX phase compound with a general formula of M_(n+1)AX_(n), where n=1 to 4, M is an early transition metal, A is an A-group element (e.g. IIIA, IVA, group 13, or group 14 element), and X is either C or N. The MAX phase compound may include, but not limited to, Nb₄AlC₃, Ti₄AlN₃, Nb₂SnC, Ti₃SnC₂, Zr₂SC, Ti₂SnC, Zr₂SnC, Nb₂PC, Nb₂AlC, Ti₃SiC₂, Ti₃AlC₂, Ti₂SC, V₂PC, or a combination thereof. Metal dopants, such as Al, Mg, Zn, Ti, or Cu, may be added into the component to further enhance the resistance of the component against hydrogen-related degradations. The protective coating material may also be mixed with other conductive and anti-corrosive compounds, including, but not limited to, nitrides (e.g. chromium nitride (CrN_(x), 0.5≤x≤2), aluminum nitride (AlN), or titanium nitride (TiN_(x), 0.3≤x≤2)), carbides, and/or oxides (e.g. titanium oxide (TiO_(x), 0.5≤x≤2), niobium oxide (NbO_(x), 1≤x≤3), or magnesium titanium oxide (MgTi₂O_(5-x), 0≤x≤5)) to enhance the conductivity and/or anti-corrosion resistance of the component. By applying a protective coating material to the at least one surface of the component may reduce the cost of manufacturing the component.

In some other embodiments, when more than one surface coating layer of the protecting coating material are applied to one surface of the component, each surface coating layer may include a different coating material to achieve a total targeting resistance capability. For example, one of the surface coating layers has a first carbide material including a first carbide compound, and another one of the surface coating layers has a second carbide material including a second carbide compound different from the first carbide compound.

In still yet another embodiment, to protect the component in the fuel cell system from hydrogen-related degradations (e.g. hydrogen embrittlement), the component made of stainless steel may not only include microstructures containing intermetallic compounds, but also at least one surface coating layer of a protecting coating material may be applied to at least one surface of the component. Specifically, on the one hand, the intermetallic compounds may be formed within the component by, for example, changing element compositions or through heat treatments. The component may include a surface region and a bulk region. Microstructures containing intermetallic compounds may precipitate at or near grain boundaries in the component or may segregate toward the surface region of the component or stay in the bulk region of the component. The intermetallic compounds may be, but not limited to, Cr₃Si, Mn₃Si, SiMo₃, SiNi₂, Mn₆Si₇Ni₁₆, MnSiNi, Si₁₂Ni₃₁, Fe₃Si, Si₃Mo₅, Mn₂FeSi, FeSi, Mn₂CrSi, MnSi, MnFe₂Si, Si₂Mo, Fe₁₁Si₅, Fe₂Si, MnNi₃, Mn₂SiMo, Fe₅Si₃, Mn₄Si₇, Ni₃Mo, FeNi₃, CrSi₂, FeSi₂, Fe₂Mo, SiNi, MnCrFeSi, Fe₇Mo₆, Ni₄Mo, FeNi, FeSiMo, Si₂Ni, CrNi₃, SiNi₃, or a combination thereof. On the other hand, the protective coating material applied to the at least one surface of the component may be a carbide material. The carbide material is a carbide compound, including, but not limited to, Ni₆Mo₆C, Cr₂₁Mo₂C₆, Mn₂₃C₆, Cr₂₃C₆, Fe₂₃C₆, Ni₂Mo₄C, Mn₃Mo₃C, Si₃Mo₅C, Fe₃Mo₃C, Cr₇C₃, Mn₇C₃, Mn₅SiC, Mn₅C₂, Mo₂C, Mn₃C, Cr₃C₂, Cr₃C, or a combination thereof. The protective coating material may also be a MAX phase material. The MAX phase material is a MAX phase compound with a general formula of M_(n+1)AX_(n), where n=1 to 4, M is an early transition metal, A is an A-group element (e.g. IIIA, IVA, group 13, or group 14 element), and X is either C or N. The MAX phase compound may include, but not limited to, Nb₄AlC₃, Ti₄AlN₃, Nb₂SnC, Ti₃SnC₂, Zr₂SC, Ti₂SnC, Zr₂SnC, Nb₂PC, Nb₂AlC, Ti₃SiC₂, Ti₃AlC₂, Ti₂SC, V₂PC, or a combination thereof.

Still referring to this embodiment, metal dopants, such as Al, Mg, Zn, Ti, or Cu, may be added into the component to further enhance the resistance of the component against hydrogen-related degradations. The protective coating material may also be mixed with other conductive and anti-corrosive compounds, including, but not limited to, nitrides (e.g. chromium nitride (CrN_(x), 0.5<x≤2), aluminum nitride (AlN), or titanium nitride (TiN_(x), 0.3≤x≤2)), carbides, and/or oxides (e.g. titanium oxide (TiO_(x), 0.5≤x≤2), niobium oxide (NbO_(x), 1≤x≤3), or magnesium titanium oxide (MgTi₂O_(5-x), 0≤x≤5)) to enhance the conductivity and/or the anti-corrosion resistance of the bipolar plates.

In addition, an interfacial contact resistance between a protective coating layer and the component in the fuel cell system may be less than 50 Ohm cm², and in other embodiments, less than 0.01 Ohm cm² during an operation of the fuel cell. An electrical conductivity value of a protective coating layer may be at least 0.1 S cm⁻¹, and in some embodiments, greater than 100 S cm⁻¹. Each protective coating layer may have a thickness of 5 nm to 1 mm, typically in a range of 50 nm and 500 μm, depending on a target conductivity.

Apart from compositions, the property of the protective coating material may also vary depending on other factors such as, defects, off-stoichiometries, microstructure or morphology (e.g. local grain boundaries, cracks, or flake sizes), and crystallinity (e.g. crystalline verse amorphous structure) of the protective coating material. A lattice mismatch between the protecting coating material and a bipolar plate may also have an impact on the local structure and/or electronic structure of the bipolar plate.

It is noted that a component made of metal substrates in an electrochemical device, such as in a fuel cell or electrolyzer system, when exposed to H₂, may not immediately react with H₂. Therefore, a H atom or H₂ sitting at a defect site, a crack, or a grain boundary of the component may consequently lead to a significant metal embrittlement of the metal substrates.

While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments can be combined to form further embodiments of the present disclosure that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics can be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes can include, but are not limited to cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, to the extent any embodiments are described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics, these embodiments are not outside the scope of the disclosure and can be desirable for particular applications. 

1.-20. (canceled)
 21. A component of an electrochemical device comprising: a substrate made of stainless steel containing a microstructure containing an intermetallic compound.
 22. The component of claim 21, wherein the substrate includes a surface region and a bulk region, the microstructure containing the intermetallic compound included in the surface region.
 23. The component of claim 22, wherein the intermetallic compound is included in the bulk region.
 24. The component of claim 21, wherein the intermetallic compound is Cr₃Si, SiMo₃, SiNi₂, MnSiNi, Si₁₂Ni₃₁, Si₃Mo₅, Mn₂FeSi, Mn₂CrSi, MnSi, MnFe₂Si, Si₂Mo, Fe₁₁Si₅, Fe₂Si, MnNi₃, Mn₂SiMo, Fe₅Si₃, Mn₄Si₇, Ni₃Mo, FeNi₃, CrSi₂, FeSi₂, Fe₂Mo, SiNi, MnCrFeSi, Fe₇Mo₆, Ni₄Mo, FeNi, FeSiMo, Si₂Ni, CrNi₃, SiNi₃, or a combination thereof.
 25. The component of claim 21, wherein the substrate is doped with at least one metal element, and the at least one metal element is Al, Mg, Zn, Ti, or Cu.
 26. A component of an electrochemical device comprising: a substrate made of stainless steel and having at least one surface; and at least one surface coating layer on each of the at least one surface, each of the at least one surface coating layer including a carbide material, the carbide material being a carbide compound, and the carbide compound being Ni₆Mo₆C, Cr₂₁Mo₂C₆, Ni₂Mo₄C, Mn₃Mo₃C, Si₃Mo₅C, Mn₇C₃, Mn₅SiC, or a combination thereof.
 27. The component of claim 26, wherein the carbide material is doped with at least one metal element, and the at least one metal element is Al, Mg, Zn, Ti, or Cu.
 28. The component of claim 26, wherein the carbide material is mixed with a nitride compound and/or an oxide compound.
 29. The component of claim 28, wherein the oxide compound is a niobium oxide (NbO_(x), 1≤x≤3) or a magnesium titanium oxide (MgTi₂O_(5-x), 0≤x≤5).
 30. The component of claim 26, wherein an interfacial contact resistance between the at least one surface coating layer and the substrate is less than 50 Ohm cm².
 31. The component of claim 26, wherein an electrical conductivity of the at least one surface coating layer is at least 0.1 S cm⁻¹.
 32. The component of claim 26, wherein each of the at least one surface coating layer has a thickness of 5 nm to 1 mm.
 33. The component of claim 26, wherein one of the at least one surface coating layer has a first carbide material including a first carbide compound, and another one of the at least one surface coating layer has a second carbide material including a second carbide compound different from the first carbide compound.
 34. A component of an electrochemical device comprising: a substrate made of stainless steel and having at least one surface; and at least one surface coating layer on each of the at least one surface, the at least one surface coating layer including a MAX phase material mixed with a nitride compound and/or an oxide compound, the MAX phase material being a MAX phase compound with a general formula of M_(n+1)AX_(n), where n=1 to 4, M is an early transition metal, A is an A-group element (e.g. IIIA, IVA, group 13, or group 14 element), and X is C or N, wherein the MAX phase compound is Nb₄AlC₃, Ti₃SnC₂, Zr₂SC, Zr₂SnC, Nb₂PC, Ti₂SC, V₂PC, or a combination thereof.
 35. The component of claim 34, wherein the MAX phase compound is Nb₄AlC₃, Ti₃SnC₂, Zr₂SC, Zr₂SnC, Nb₂PC, or a combination thereof.
 36. The component of claim 34, wherein the oxide compound is a titanium oxide (TiO_(x), 0.5≤x≤2), a niobium oxide (NbO_(x), 1≤x≤3), or a magnesium titanium oxide (MgTi₂O_(5-x), 0≤x≤5).
 37. The component of claim 34, wherein the MAX phase material is doped with at least one metal element, and the at least one metal element is Al, Mg, Zn, Ti, or Cu.
 38. The component of claim 34, wherein an interfacial contact resistance between the at least one surface coating layer and the substrate is less than 50 Ohm cm².
 39. The component of claim 34, wherein an electrical conductivity of the at least one surface coating layer is at least 0.1 S cm⁻¹.
 40. The component of claim 34, wherein one of the at least one surface coating layer has a first MAX phase material including a first MAX phase compound, and another one of the at least one surface coating layer has a second MAX phase material including a second MAX phase compound different from the first MAX phase compound. 